1. Technical Field of the Invention
The present invention relates generally to tire pressure monitoring systems for vehicles and wireless communication systems.
More particularly, the invention relates to a tire pressure monitoring system for a vehicle, in which wheel-based transceivers provide tire pressure information to a vehicle body-based transceiver via reliable wireless communication therebetween.
2. Description of the Related Art
A conventional tire pressure monitoring system for a vehicle includes a plurality of transmitters and a receiver and monitors the inflation pressure of tires of the vehicle via wireless communication between the transmitters and the receiver.
Specifically, in the tire pressure monitoring system, each of the transmitters is mounted on a wheel of the vehicle and includes a pressure sensor working to sense the inflation pressure of a tire fitted on the wheel. Each of the transmitters is configured to transmit a tire pressure signal that conveys tire pressure information on the inflation pressure of the tire sensed by the pressure sensor.
On the other hand, the receiver is mounted on the body of the vehicle. The receiver is configured to receive the tire pressure signals transmitted by the transmitters, determine the inflation pressure of the tires based on the tire pressure information conveyed by the received tire pressure signals, and perform various suitable processes based on the determined inflation pressure of the tires, such as displaying the determined inflation pressure of the tires and warning a flat tire condition of the tires.
Further, in the tire pressure monitoring system, each of the transmitters has identification specific thereto and transmits identification information on the specific identification along with the tire pressure information. Then, the receiver determines whether tire pressure information received thereby is transmitted by one of the transmitters on the vehicle or by a transmitter on another vehicle based on the identification information received thereby along with the tire pressure information.
However, with such a configuration, it is necessary for each of the transmitters to store therein the identification information, thus increasing the memory capacity thereof. Moreover, it is also necessary for each of the transmitters to transmit the identification information along with the tire pressure information, thus increasing the total amount of information required to be transmitted thereby.
Further, with the increased amount of information required to be transmitted, the electric power required for operation of each of the transmitters is accordingly increased. Thus, when the tire pressure monitoring system is of a batteryless type, in which each of the transmitters is supplied with electric power via a radio wave transmitted by a vehicle body-based transmitter (or transceiver) without any battery, the time required for each of the transmitters to receive the radio wave is accordingly increased.